hoffman



(No Model.)

B. J. HOFFMAN.

DAMPER REGULATOR.

W M V p om l I w W I w N m m Du M P w k7 1 k m E\ M L NE/m1 11;Ww/ym/wiiwiw/EM/11%, p N i? E 7 0 L H Z W 3 T W0 m y 2 lINrTEo Sra'rnsROSS J. HOFFMAN, OF BING-I-IAMTON, NEW YORK.

DAMPER REGULATOR.

SPECIFICATION forming part of Letters Patent No. 392,51 dated November6, 1888.

Application filed May 1, 1888. Serial No. 272,449. (No model.)

To aZZ whom it may concern:

Be it known that I, Ross J. HOFFMAN, ol' Binghamton, in the county ofBroome and State of New York, have invented a new and useful Improvementin Damper-Regulators; and I do hereby declare that the following is afull, clear, and exact description of the same.

My invention is an improvement in damperregulators for controlling thefire under steamboilers of that class which are actuated by the steamoperated through a regulating valve upon a piston working in thecylinder and connected to the damper.

The invention consists, first, in the combination, with a piston and asteanr passage communicating with the cylinder at one end to raise thepiston, of a regulator-valve in said passage and an open steampassagecommunicating with the other end of the cylinder, whereby the piston ismoved in both directions through the agency of the steam to open orclose the damper.

My invention further consists in inter-posing a yielding connectionbetween the piston and the steanrcontrolling valve, whereby the movementof the piston under the excessive pressure of the steam may aid inreturning the valve to its seat to cut oil. the steam from the cylinder.

In the accompanying drawingsJFigure 1. represents my improved apparatuswith the valves and pipes in central vertical section, and Fig. 2 showsthe invention applied to a steamboiler.

In the drawings, A represents a cylinder,in which works a piston, 13,the outer end of which is connected to the damper O in the ordinarymanner, so that when the piston is forced outward the damper is closedand when the piston returns the damper is opened. The piston worksthrough a stuffing-box, as shown; but any convenient means for closingthe end of the cylinder may be used. The casting D forms an intermediateconnection between the cylinder and the boiler or support thereof towhich the apparatus is attached. In a recess in this is located thepressure-valve E, which when on its seat closes the opening between thesteanrpassages c c. Ihave shown aspring, F, for applying the pressure tothis valve, as the more convenient means; but a weight may be used asthe well-known equivalent of the spring for this purpose. The plug Gserves to adjust the tension of the spring to the amount ofsteam-pressure required. The stem of the valve extends through the plugand is connected to the piston at its outer end to cause the piston inmovingoutward to aid in closing the valve. This connection, as shown ininy patent, No. 347,799, granted August 24, 1886, is rigid and positive,so that after the piston begins to operate upon the connection it actspositively on the valve. In order to modify this positive action, Iinterpose a spring between the valve and the piston, so that the firstpart of the movement of the piston is taken up by the spring and theforce of the moving. piston is exerted on the valve gradually as thetension of the spring increases. connection shown is not material, butis simple and effective. It consists of a bell-crank lever, y, pivotedon an arm on the casting,one end of the lever being connected to thevalvestem and the other to a rod, H, extending alongside ofthe cylinder.A spring, K, coiled around the rod and connected therewith at the lowerend, is also connected at its upper end with the outer end of the pistonby means of an arm, L. When the piston rises or is forced out, itsmovement extends the spring, and

The precise form of thus draws upon the rod and tends to aid the springin pressing the valve to its seat with a gradual pressure, and thusgradually moves the damper in closing as the steam rises. It thus isfitted to gradually meet the rising steam and control the fire until theamount of fireis adapted to the required amount of steam, whereas in theregulator shown in my said patent the tendency of the piston movementwas to close the valve suddenly, and not to open it until the steam hadconsiderably fallen, thus causing a more uneven action. In order tolimit the movement of the piston after it has done its work, and toprevent any more steam from entering the cylinder thereafter, whichwould be useless and tend to cause leaking around the piston, I place anadjustable stop, h, on the rod, with a buder-spring, Z, between it toprevent injury to the connections.

To cause the prompt release of the piston after it has acted in closingor partially elos ing the damper to a proper extent, I provide asteaurpassage to the upper end of the cyl indcr. In the form shown thispassage consists of a pipe, M, constantly open, so that somesteam-pressure is always on the upper 5 side of the piston; and tolessen this, in order that the steam on the other side may move it, Ireduce the surface on the upper side by on larging the stem, so that thesurface is (for example) about one-half that of the lower side. I

The difference in pressure is sufficient to move the piston. Adrip-cock, m, is placed in the chamber in which the valve is located,which may be left open su flicicntly to allow the escape of the water ofcondensation and any steam that may be inclosed when the valve is on itsseat. The lower end ofthe pipe M is joined to a union which may hold thecasting to the stem on the boiler; but these are immaterial details,which may be left to the skill of the work man.

I have described the yielding connection be tween the piston and thepressure-valve to consist of a spring. This is the simplest and best;but of course a weight is well known as an equivalent for a spring, andmay be used instead of the spring.

The damper is shown at c and is in connection to the piston by rods a b.e

I do not claim, broadly, enough to include 0 ajointed conneetingrodbetween a piston and V "/valve.

I claim as my invention 1. In combination with the piston and steam- 2.In combination with the piston and steam pressure valve of adamper-regulator, a springconneetion continuous between the piston andthe steam-pressure valve, whereby the action of the piston in closingthe valve is made gradual, substantially as described.

3. In combination with the piston and a steam-pressure valve in adamper-regulator, a bell'crank lever, a rod connected thereto, and aspring connected to the piston, with an adjustable buffer-stop on therod, substantially as described.

t. In combination with the piston, a steamvalve, a yielding connectionbetween the two, said valve being arranged in a steam-passage leading tothe cylinder at the bottom of the piston, and a steam-passage leadingfrom the inlet to the upper side of the piston for returning it,substantially as described.

5. In combination with the piston andsteampressure valve of adamper-regulator, ayielding connection continuous between said pistonand valve, said piston having unequal steamsurfaces, a steam-passagecontrolled by said valve leading directly to the lower andlarger face ofthe piston, and a second steam-passage leading to the opposite andsmaller face of the piston, said second passage being always open,substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witncSScS.

ROSS J. 'l'lOFFlll'AN.

'Witnesscs:

WALTER DONA'LDSON, ROBERT E. Mounts.

